As the control device for the continuously variable transmission of this type, a control device described in Patent Publication 1 has been suggested. In a technique described in this Patent Publication 1, in the cases where a rotational speed of a primary pulley becomes higher than a value that is obtained by multiplying a maximum gear ratio that can be obtained as a mechanism by a rotational speed of a secondary pulley and where an engine speed is at least equal to a specified value, a determination of belt slippage is made, and belt slippage protection control is executed.
However, there is a case where an engine reaches a high speed and causes vibration of the primary pulley when an accelerator pedal is operatively depressed in a state where a driver sets a shift lever in a P range or an N range. Depending on a position of the primary pulley, a sensor for detecting the rotational speed of the primary pulley possibly outputs a pulse signal due to such vibration, and, in this case, the control device erroneously recognizes the mere vibration as rotation of the primary pulley. Because a vehicle is at a stop, and the secondary pulley does not rotate at this time, such a problem that occurrence of the belt slippage is determined and the belt slippage protection control is executed arises.